Do solar-powered vehicles have a viable future asks Ian Draisey

A number of concept cars with solar-powered capability have been showcased at motor shows in recent years. Many manufacturers claim that their technology is pushing the boundaries, but the average car roof simply does not provide enough space to generate the power needed to propel anything more than a featherweight vehicle. Current solar-powered car endurance competitions are invariably held in locations where there are high levels of solar irradiation and very little cloud cover, such as the Australian Outback or Chile’s Atacama Desert. The ‘cars’ are ultra-lightweight, one-person vehicles designed to have the highest amount of surface area possible completely covered by solar cells.

The technology used in these vehicles varies. Some use the power to directly run the vehicle’s motor (or motors), while others use the power to charge multiple batteries and provide a more consistent power source to the motor. Both vehicle and solar technology manufacturers have commendably invested millions in making them work efficiently. As we know, it is this level of investment and boundary pushing that helps technology grow and reach viability ‘tipping-points.’

As the efficiency of lithium-ion batteries or similar battery technology improves and the take-up of electric vehicles increases, we will inevitably see better performance and reductions in the price. But for the foreseeable future, this doesn’t overcome the issue of generating enough power to move a significantly heavier vehicle and multiple occupants over a useful distance.

The potential for solar-powered vehicles lies in the principal of harnessing the sun’s power from a static solar PV array to charge an electric vehicle’s battery system. This is where the future of electric — and more specifically solar-powered — vehicles will have the best opportunity of becoming a viable option for transport.

Picture this ideal scenario: a solar PV array on a car port or charging station roof could charge a car while the owner is sat at their office desk during daylight hours. Another set of batteries is charging from the driver’s PV array back at home. The driver could then return home in the charged vehicle that evening and simply swap the fully charged batteries for evening journeys and the emission-free drive back to work the next day.

Right now, lithium-ion battery design does not allow for this interchange as their weight, the safety requirements and charging time means that they must be connected to the main power grid, especially for ‘fast’ charging.

In light of the recent VW admission, where VW cars have allegedly been cheating emissions regulations, Greenpeace has launched a campaign calling on supporters to sign a petition. This petition could force VW to mass-produce a commercially viable electric car (or even solar-powered car) and bring electric cars closer to the mainstream. It will be interesting to see how developments pan out over the next months and years, and whether something genuinely positive comes from this negative scandal.

With the level of potential investment and further economy of scale that such a large organisation could bring, it really could make a difference to the potential of solar power to move people around in their everyday lives. While solar-powered vehicles are some way off being a viable commercial option, we all need to encourage and support the manufacturers that are pushing the technology to help protect all our futures.

BayWa Solar Systems
Ian Draisey is the Managing Director at BayWa r.e. Solar Systems Ltd, one of the UK’s leading wholesale suppliers to the solar PV installer network. Headquartered in Machynlleth, mid- Wales and operating across the UK and Ireland, BayWa r.e. is an approved ISO 9001:2008 company for the procurement and supply of high-quality products for solar PV applications. As part of the German BayWa r.e. renewable energy GmbH group of companies, BayWa r.e. Solar Systems offers competitive pricing with direct access to Europe-wide stocks of high quality, high profile solar PV brands and products.

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